Imaging Flashcards
what are X-rays
uses electromagnetic waves to produce images
what is the first type of imaging that will be provided
x-ray
dense material - x-ray
shows up white
bone and metal
black - x-ray
air in lungs
shades of grey- x-ray
fat and muscles
when is x-ray used - bone and teeth
fx and infections
bone tumours
osteoporosis
when i x-ray used -chest
lung infections/conditions (pneumonia, tuberculosis)
breast cancer
enlarged heart
when is x-ray used - abdomen
swallowed items
GI tracts problems (barium contrast medium)
A
alignment : fx, subluxation, dislocation
joint space: narrowing due to cartilage loss, calcification, new bone formation
B
bone texture : altered density or disruption
C
cortices: trace around the bone as a step on the cortex may indicate fx or other pathology
S
soft tissue: swelling, foreign bodies or effusion
X-ray examples
see ppt
risks of x-ray
small amount of radiation exposed o is safe
has been linked to cancer
safe for adults
not safe for developing fetus
children more sensitive to radiation
CT scan
combines a series of x-ray images taken from different angles and uses computer processing to create cross sectional images of bone, vessels or soft tissue inside the body
why use a CT scan
diagnose muscle or bone disorder
pinpoint location of infection, tumor or fx
guide procedure like surgery, biopsy and radiation therapy
detect and monitor diseases and conditions such as cancer, heart disease, lung nodules and liver masses
monitor the effectiveness of certain treatments such as cancer
detect internal injuries and internal bleeding
what allows radiologist to evaluate meniscus tear or chondromalacia patella
fluid that turns white on the image
injection of isotopes?
diagnostic US characteristics
no radiation
quick
portable
low cost
done over metal
can be done dynamically
US
high frequency sound waves that bounces off of tissues and organs to create a multi-dimensional image
what is US good for
capturing soft tissues, muscles and ligaments
gold standard for RC tears
US and CT scan
MRI
technique that uses magnetic field and radio waves to create detailed images of organs and tissues in the body
how does MRI work
magnetic field temporarily realigns hydrogen atoms in your body
radio waves cause these aligned atoms to produce very faint signals which are used to create cross-sectional MRI images
produces 3D images that can be looked at from different angles
no radiation
MRI helps evaluate
joint abnormalities causes by traumatic or repetitive injuries such as torn cartilage or ligaments
disc abnormalities in the spine
bone infection
tumors of the bone and soft tissues
MRI for brain and spinal cord can help diagnose
aneurysms of cerebral vessels
disorders of the eye and inner ear
multiple sclerosis
SC injuries
stroke
tumors
brain injury from trauma
MRI for heart and BV assesses for
size and function of the heart’s chambers
thickness and mvt of the walls of the heart
the extent of damage caused by heart attack or heart disease
structural problems in the aorta, such as aneurysms or dissections
inflammation or blockages in the blood vessels
MRI for internal organs
check for tumors or abnormalities of:
liver and bile ducts
kidneys
spleen
pancreas
uterus
ovaries
prostate
absolute contraindications of MRI
cardiac implantable electronic device
metal pieces
drug infusion pump
artificial limb
hearing aid
relative contraindication of MRI
tattoos less than 6 weeks old
shunts
medication patch
joint replacement or prosthesis
pt unable to obey breathing instructions or has severe claustrophobia
BMI
Open MRI
larger opening
image quality is directly proportional to magnetic field strength
less diagnostic info (less strong)
T1 vs T2
see table
DEXA scan
bone density test
uses low levels of x-ray to measure how dense your bones are
goal of DEXA
designed to measure density of body tissue
does not produce high quality picture
dexa measures
mineral content of the bones in certain area of the skeleton
bone loss
common use for DEXA
diagnose OA
compare BMD and normal for age
bone scan use
detect stress fx of the long bones and vertebrae
DD
infections bone
tumors of the bone
fibrous dysplasia
paget’s disease
avascular necrosis
arthritis
shows disturbance but not define nature of disturbance
bone scan
looks at bone metabolism
injection of isotopes several hours before scan to show increased areas of increased activity
x-rays do not show stress fx unless
30-50% of bone loss
abnormal bone scan
shows darker hot spots or lighter cold spots
EMG use
used as a diagnistic procedure to assess the health of muscles and the nerve cells that control them
reveal nerve dysfunction, muscle dysfunction or problems with nerve to muscle signal transmission
why get EMG
tingling
numbness
muscle weakness
muscle pain/cramping
EMG diagnose/rule out
muscle disorders
diseases affecting the connection between nerve and muscle
dicorder of nerves outside the SC
disorders that affect motor neurons in the brain/SC
disorders that affect the nerve root (herniated disc)
Cost of MRI in canada
1000-3000$ +300 contrast
US cost
500$+500 if injection
X-ray cost
100-1000$
average 260-460$
